MONDAY, June 29, 2015 (HealthDay News) -- Women who have been through a traumatic event or developed post-traumatic stress disorder (PTSD) face an increased risk of heart attack or stroke, a new large study suggests.

For women with severe PTSD, the study found a 60 percent higher risk of heart attack or stroke compared to women who hadn't experienced any trauma. The risk was increased 45 percent for women who experienced a traumatic event but didn't develop PTSD, the researchers added.

"Our study is the first to look at trauma exposure and PTSD symptoms and new cases of cardiovascular disease in a general population sample of women," said lead researcher Jennifer Sumner, an epidemiologist at Columbia University's Mailman School of Public Health in New York City.

It's important to note, however, that while this study found an association between trauma and a higher risk of stroke and heart attack, it wasn't designed to prove a cause-and-effect relationship. It's possible that other factors may explain the increased risk.

The report was published online June 29 in the journal Circulation.

Symptoms of PTSD include: avoiding reminders of the trauma; having nightmares or flashbacks of the trauma; having trouble sleeping; being irritable; or startling easily, Sumner explained.

Some of the women in the study developed PTSD after experiencing traumatic and extremely stressful events, such as unwanted sexual contact, the unexpected death of a loved one and physical assault, she said.

"PTSD is twice as common in women as in men. Approximately one in 10 women will develop PTSD in their lifetime," she noted. "Research has begun to suggest that rates of cardiovascular disease are higher in people with PTSD. However, almost all research has been done in men."

Besides being a psychological problem, PTSD also increases the risk of chronic disease, she said.

For the study, Sumner and her colleagues reviewed data from almost 50,000 women who took part in the Nurses' Health Study II.

Almost 35,000 of the women had been through a traumatic event. Just under 10,000 women had symptoms of PTSD, the study found. During the 20-year follow-up period, 548 women suffered a heart attack or a stroke, the study said.

Women with PTSD should be aware that they may have an increased risk of heart attack or stroke, Sumner said. And women with PTSD need to know that engaging in unhealthy behaviors, such as smoking cigarettes and eating an unhealthy diet, may increase this risk even more, she added.

"PTSD is generally considered a psychological problem, but it also has a profound impact on physical health, especially cardiovascular risk," she said.

Health care providers treating women at risk for PTSD, including primary care physicians, should screen them for risks for heart attack and stroke, Sumner said.

"Psychological treatment for PTSD also needs to consider the long-term health consequences of the disorder. Ultimately, integration of mental and physical health care is key," she said.

Dr. Gregg Fonarow, a professor of cardiology at the University of California, Los Angeles, said, "Prior studies have suggested that a variety of psychological and social stressors are associated with increased risk of heart attack and stroke."

Some studies have found that PTSD is associated with excess risk, but many of these studies have been confined to men, he noted.

This study shows that women with PTSD symptoms are also more likely to experience heart attacks and stroke. It also showed that as much as half of the increased risk was related to unhealthy behaviors and risk factors, such as high blood pressure, Fonarow said.

Fonarow said that women who have experienced traumatic events or who have PTSD can cut their risk for heart attack and stroke by controlling traditional risk factors.

"People with increased risk should take proactive steps to lower this risk through adopting heart-healthy behaviors, such as not smoking and achieving healthy levels of body weight, blood pressure and cholesterol," Fonarow said.